Blue Sea ACR via batt switches vs. batt directly?

[jms28]

Hi,

While installing a new battery charger today, I discovered that the last yard our boat was in has connected our Blue Sea ACR via our battery switches rather than going to the batteries directly. In the manufacturer's manual it says the following:

It is recommended that the ACR be connected directly to your battery positive terminals through appropriately sized fuses. Connecting in a different location such as a battery switch may affect accuracy because of voltage drop along current carrying conductors.

Here a diagram of our current wiring, which obviously doesn't follow Blue Sea's recommendation:



Is this problematic in your view? Does anyone else here have an ACR fitted this way? Not 100% sure but I had a feeling last year that my starter battery was pulled down by the service bank at times, could this be the reason?

Thanks

 

[pvb]

Is this problematic in your view? Does anyone else here have an ACR fitted this way? Not 100% sure but I had a feeling last year that my starter battery was pulled down by the service bank at times, could this be the reason?

I don't think it's a big problem, although you don't say whether the ACR leads are fused - they should be.

Your starter battery shouldn't be affected by the ACR. THe ACR only connects when there's a charging source available.

 

[VicS]

I agree.
Provided all the leads are heavy enough relative to their length for the current they will carry without excessive volts drop there should be no problem, but if you are not convinced rewire it as Blue Sea recommend
The fuses should be rated so that the max rating of the ACR cannot be exceeded. Strictly speaking only one fuse is needed tp protect the ACR from overcurrent, but fit both if the leads are not very short and direct.

I would also fit a switch in the negative connection of the ACR so that is can be disabled in the event of a bad battery having to be isolated and everything powered via te emergency crossover switch from the good battery.
Maybe your starter battery was being "pulled down" because you had inadvertently closed the emergency crossover switch ?

 

[PaulRainbow]

Connecting to the battery switches is usually OK, providing that the cabling is rated to prevent excess voltage drop. In a system, such as your, where the engine can be started from the domestic bank by an emergency switch, all cables are normally rated to that which is needed to start the engine (pointless switch installation otherwise.). In which case, connecting to the switches, as per your diagrasm, is perfectly OK.

PVB does mention fuses, which is a valid point.